Medical devices and implements with liquid-impregnated surfaces

ABSTRACT

Described herein are medical devices and medical implements with high lubricity to flesh (or biological fluid) and/or inhibited nucleation on its surface. The device has a surface comprising an impregnating liquid and a plurality of micro-scale and/or nano-scale solid features spaced sufficiently close to stably contain the impregnating liquid therebetween. The impregnating liquid fills spaces between said solid features, the surface stably contains the impregnating liquid between the solid features, and the impregnating liquid is substantially held in place between the plurality of solid features regardless of orientation of the surface.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/476,708, filed Mar. 31, 2017, which is a continuation of U.S. patentapplication Ser. No. 13/902,614, filed May 24, 2013, which claimspriority to and the benefit of U.S. Provisional Patent Application No.61/651,543, filed on May 24, 2012, each of which are hereby incorporatedherein by reference in their entireties.

TECHNICAL FIELD

This invention relates generally to liquid-impregnated surfaces. Moreparticularly, in certain embodiments, the invention relates to medicaldevices and implements with liquid-impregnated surfaces.

BACKGROUND

The advent of micro/nano-engineered surfaces in the last decade hasopened up new techniques for enhancing a wide variety of physicalphenomena in thermofluids sciences. For example, the use of micro/nanosurface textures has provided nonwetting surfaces capable of achievingless viscous drag, reduced adhesion to ice and other materials,self-cleaning, and water repellency. These improvements result generallyfrom diminished contact (i.e., less wetting) between the solid surfacesand adjacent liquids.

Liquid-impregnated surfaces are described in U.S. patent applicationSer. No. 13/302,356, published as US 2013/0032316, entitled,“Liquid-Impregnated Surfaces, Methods of Making, and DevicesIncorporating the Same,” by Smith et al.; U.S. patent application Ser.No. 13/517,552, entitled, “Self-Lubricating Surfaces for Food Packagingand Food Processing Equipment,” by Smith et al.; and U.S. ProvisionalPatent Application No. 61/827,444, filed May 24, 2013, entitled,“Apparatus and Methods Employing Liquid-Impregnated Surfaces,” by Smithet al., the texts of which are incorporated herein by reference in theirentireties.

There is a need for medical devices and implements with high lubricityto flesh (or biological fluid) and/or inhibited nucleation on thesurface of the device/implement.

SUMMARY OF THE INVENTION

Described herein are medical devices and implements withliquid-impregnated surfaces for enhanced lubricity to flesh (orbiological fluid) and/or inhibited nucleation on the surface of thedevice/implement.

In one aspect, the invention provides a medical device or medicalimplement with high lubricity to flesh (or biological fluid) and/orinhibited nucleation on its surface, the device or implement includes asurface comprising an impregnating liquid and a plurality of micro-scaleand/or nano-scale solid features spaced sufficiently close to stablycontain the impregnating liquid therebetween. In certain embodiments,the impregnating liquid fills spaces between said solid features and thesurface stably contains the impregnating liquid between the solidfeatures. In certain embodiments, the impregnating liquid issubstantially held in place between the solid features regardless oforientation of the surface.

In certain embodiments, the solid features comprise particles having anaverage dimension in a range of 1 micron to 50 microns (e.g., 5 micronsto 50 microns). The particles may be arranged with average spacing ofabout 1 micron to about 30 microns between adjacent particles orclusters of particles (e.g., 10 microns to 30 microns). The particlesmay be spray-deposited.

In certain embodiments, the impregnating liquid includes at least onemember selected from the group consisting of ethyl oleate, an ester, afatty acid, a fatty acid derivative, a vegetable oil (e.g., olive oil,light olive oil, corn oil, soybean oil, rapeseed oil, linseed oil,grapeseed oil, flaxseed oil, canola oil, peanut oil, safflower oil,sunflower oil), a terpene, phenyl isothiocyanate (phenyl mustard oil),bromobenzene, iodobenzene, o-bromotoluene, alpha-chloronaphthalene,alpha-bromonaphthalene, acetylene tetrabromide,1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (BMIm),tribromohydrin (1,2,3-tribromopropane), ethylene dibromide, carbondisulfide, bromoform, methylene iodide (diiodomethane), stanolax,Squibb's liquid petrolatum, p-bromotoluene, monobromobenzene,perchloroethylene, carbon disulfide, phenyl mustard oil,monoiodobenzene, alpha-monochloro-naphthalene, acetylene tetrabromide,aniline, butyl alcohol, isoamyl alcohol, n-heptyl alcohol, cresol, oleicacid, linoleic acid, and amyl phthalate.

In certain embodiments, the solid features include one or more membersselected from the group consisting of wax, carnauba wax, beeswax,candelilla wax, zein (from corn), dextrin, cellulose ether, hydroxyethylcellulose, hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose,hydroxypropyl methyl cellulose (HPMC), ethyl hydroxyethyl cellulose,insoluble fiber, purified wood cellulose, micro-crystalline cellulose,kaolinite (clay mineral), Japan wax, pulp (e.g., spongy part of plantstems), ferric oxide, iron oxide, sodium formate, sodium oleate, sodiumpalmitate, sodium sulfate, a metal, a polymer, a ceramic solid, afluorinated solid, an intermetallic solid, and a composite solid PDMS,cyclic olefin polymer, polypropylene, PVC, PET, HDPE, polyimide, PMMA,glass, Perspex, Plexiglass, Polymacon.

The impregnating liquid may include an additive to prevent or reduceevaporation of the impregnating liquid. The medical device or medicalimplement may be a member selected from the group consisting of braces,dentures, a retainer, orthodonture, a bridge, an implant, a tooth/teethmold, a prosthesis, an artificial organ, an artificial artery, a stent,a syringe, a lining (e.g., lining for artery walls to prevent plaqueformation), an IV tube, an IV bag, a colostomy bag, a surgicalinstrument, a bandage, and a blood pump.

The medical device or medical implement may be a blood pump or partthereof. The surface may be configured to provide reduction of shearforces to prevent damage to cells and/or other biological structures inblood or other biological fluids being pumped thereby or therethrough.The medical device or medical implement may be a member selected fromthe group consisting of a pill, capsule (e.g., single-piece ortwo-piece), tablet, gel cap, and suppository.

The medical device or medical implement may be a member selected fromthe group consisting of a micropipette, a small volume container ofbiological material, a human serum container, a pipette, a pipette tip,a microfluidic device, a dialysis machine, a tube, an endoscope, anintubation device, a syringe, a stent, a catheter, and a tracheotomytube.

The medical device or medical implement may be a member selected fromthe group consisting of a glove, bandage, adhesive strip, drug releasepatch, and condom. The impregnating liquid may be an antiseptic and/oran antibacterial. The impregnating liquid may be curable and can beconverted to a solid by curing (e.g., exposure to heat).

In some implementations, one or both of the following holds: (i)0<ϕ≤0.25, where ϕ is a representative fraction of the projected surfacearea of the liquid-impregnated surface corresponding to non-submergedsolid at equilibrium; and (ii) S_(ow(a))<0, where S_(ow(a)) is spreadingcoefficient, defined as γ_(wa)-γ_(wo)-γ_(oa), where γ is the interfacialtension between the two phases designated by subscripts w, a, and o,where w is water, a is air, and o is the impregnating liquid. In someimplementations, 0<ϕ≤0.25. In some implementations, 0<ϕ≤0.10. In someimplementations, 0.01<ϕ≤0.25. In some implementations, 0.01<ϕ≤0.10. Insome implementations, S_(ow(a))<0.

In some implementations, one or both of the following holds: (i)θ_(os(w),receding)=0; and (ii) θ_(os(a),receding)=0 andθ_(os(w),receding)=0, where θ_(os(w),receding) is receding contact angleof the impregnating liquid (e.g., oil, subscript ‘o’) on the surface(subscript ‘s’) in the presence of water (subscript ‘w’), and whereθ_(os(a),receding) is receding contact angle of the impregnating liquid(e.g., oil, subscript ‘o’) on the surface (subscript ‘s’) in thepresence of air (subscript ‘a’).

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features of the invention can be better understood withreference to the drawing described below, and the claims.

FIG. 1 illustrates a schematic cross-sectional and corresponding topview of a liquid-impregnated surface that are partially submerged;

FIGS. 2A and 2B demonstrate the effectiveness of liquid-impregnatedsurface coatings on tweezers to shed off blood;

FIGS. 3A and 3B demonstrate that liquid-impregnated surface pills slidemore easily on animal tissue than uncoated pills;

FIGS. 4A and 4B demonstrate that animal flesh slides more easily onliquid-impregnated surfaces than on uncoated surfaces;

FIGS. 5A though 5D illustrate a mold-release experiment using concreteand a liquid-impregnated surface coated mold;

FIG. 6 illustrates a sold-to-solid adhesion experiment for determiningthe adhesion strength of liquid-impregnated surfaces;

DETAILED DESCRIPTION

It is contemplated that compositions, mixtures, systems, devices,methods, and processes of the claimed invention encompass variations andadaptations developed using information from the embodiments describedherein. Adaptation and/or modification of the compositions, mixtures,systems, devices, methods, and processes described herein may beperformed by those of ordinary skill in the relevant art.

Throughout the description, where articles, devices, apparatus andsystems are described as having, including, or comprising specificcomponents, or where processes and methods are described as having,including, or comprising specific steps, it is contemplated that,additionally, there are articles, devices, apparatus and systems of thepresent invention that consist essentially of, or consist of, therecited components, and that there are processes and methods accordingto the present invention that consist essentially of, or consist of, therecited processing steps.

Similarly, where articles, devices, mixtures, apparatus and compositionsare described as having, including, or comprising specific compoundsand/or materials, it is contemplated that, additionally, there arearticles, devices, mixtures, apparatus and compositions of the presentinvention that consist essentially of, or consist of, the recitedcompounds and/or materials.

It should be understood that the order of steps or order for performingcertain actions is immaterial so long as the invention remains operable.Moreover, two or more steps or actions may be conducted simultaneously.

The mention herein of any publication, for example, in the Backgroundsection, is not an admission that the publication serves as prior artwith respect to any of the claims presented herein. The Backgroundsection is presented for purposes of clarity and is not meant as adescription of prior art with respect to any claim.

Described herein are surfaces comprising an impregnating liquid and aplurality of micro-scale and/or nano-scale solid features spacedsufficiently close to stably contain the impregnating liquidtherebetween, wherein the impregnating liquid fills spaces between thesolid features, wherein the interior surface stably contains theimpregnating liquid between the solid features, and wherein theimpregnating liquid is substantially held in place between the pluralityof solid features.

In certain embodiments, the solid features may be part of the surfaceitself (e.g., the surface may be etched or otherwise textured to createthe solid features), or the solid features may be applied to thesurface. In certain embodiments, the solid features include anintrinsically hydrophobic, oleophobic, and/or metallophobic material orcoating. For example, the solid features may be made of: hydrocarbons,such as alkanes, and fluoropolymers, such as teflon,trichloro(1H,1H,2H,2H-perfluorooctyl)silane (TCS),octadecyltrichlorosilane (OTS),heptadecafluoro-1,1,2,2-tetrahydrodecyltrichlorosilane, fluoroPOSS,and/or other fluoropolymers. Additional possible materials include:ceramics, polymeric materials, fluorinated materials, intermetalliccompounds, and composite materials. Polymeric materials may include, forexample, polytetrafluoroethylene, fluoroacrylate, fluoroeurathane,fluorosilicone, fluorosilane, modified carbonate, chlorosilanes,silicone, polydimethylsiloxane (PDMS), and/or combinations thereof.Ceramics may include, for example, titanium carbide, titanium nitride,chromium nitride, boron nitride, chromium carbide, molybdenum carbide,titanium carbonitride, electroless nickel, zirconium nitride,fluorinated silicon dioxide, titanium dioxide, tantalum oxide, tantalumnitride, diamond-like carbon, fluorinated diamond-like carbon, and/orcombinations thereof. Intermetallic compounds may include, for example,nickel aluminide, titanium aluminide, and/or combinations thereof.

The solid features of a liquid-impregnated surface may form physicaltextures or surface roughness. The textures may be random, includingfractal, or patterned. In certain embodiments, the textures aremicro-scale or nano-scale features. For example, the textures may have alength scale L (e.g., an average pore diameter, or an average protrusionheight) that is less than about 100 microns, less than about 10 microns,less than about 1 micron, less than about 0.1 microns, or less thanabout 0.01 microns. In certain embodiments, the texture includes postsor other protrusions, such as spherical or hemispherical protrusions.Rounded protrusions may be preferable to avoid sharp solid edges andminimize pinning of liquid edges. The texture may be introduced to thesurface using any conventional method, including mechanical and/orchemical methods.

In certain embodiments, the solid features include particles. In certainembodiments, the particles have an average characteristic dimension in arange, for example, of about 5 microns to about 500 microns, or about 5microns to about 200 microns, or about 10 microns to about 50 microns.In certain embodiments, the characteristic dimension is a diameter(e.g., for roughly spherical particles), a length (e.g., for roughlyrod-shaped particles), a thickness, a depth, or a height. In certainembodiments, the particles include insoluble fibers, purified woodcellulose, micro-crystalline cellulose, oat bran fiber, kaolinite (claymineral), Japan wax (obtained from berries), pulp (spongy part of plantstems), ferric oxide, iron oxide, sodium formate, sodium oleate, sodiumpalmitate, sodium sulfate, wax, carnauba wax, beeswax, candelilla wax,zein (from corn), dextrin, cellulose ether, Hydroxyethyl cellulose,Hydroxypropyl cellulose (HPC), Hydroxyethyl methyl cellulose,Hydroxypropyl methyl cellulose (HPMC), and/or Ethyl hydroxyethylcellulose. In certain embodiments, the particles include a wax. Incertain embodiments, the particles are randomly spaced. In certainembodiments, the particles are arranged with average spacing of about 1micron to about 500 microns, or from about 5 microns to about 200microns, or from about 10 microns to about 30 microns between adjacentparticles or clusters of particles. In certain embodiments, theparticles are spray-deposited (e.g., deposited by aerosol or other spraymechanism).

In some embodiments, micro-scale features are used. In some embodiments,a micro-scale feature is a particle. Particles can be randomly oruniformly dispersed on a surface. Characteristic spacing betweenparticles can be about 200 μm, about 100 μm, about 90 μm, about 80 μm,about 70 μm, about 60 μm, about 50 μm, about 40 μm, about 30 μm, about20 μm, about 10 μm, about 5 μm or 1 μm. In some embodiments,characteristic spacing between particles is in a range of 100 μm to 1μm, 50 μm to 20 μm, or 40 μm to 30 μm. In some embodiments,characteristic spacing between particles is in a range of 100 μm to 80μm, 80 μm to 50 μm, 50 μm to 30 μm or 30 μm to 10 μm. In someembodiments, characteristic spacing between particles is in a range ofany two values above.

Particles can have an average dimension of about 200 μm, about 100 μm,about 90 μm, about 80, about 70 μm, about 60 μm, about 50 μm, about 40μm, about 30 μm, about 20 μm, about 10 μm, about 5 μm or 1 μm. In someembodiments, an average dimension of particles is in a range of 100 μmto 1 μm, 50 μm to 10 μm, or 30 μm to 20 μm. In some embodiments, anaverage dimension of particles is in a range of 100 μm to 80 μm, 80 μmto 50 μm, 50 μm to 30 μm, or 30 μm to 10 μm. In some embodiments, anaverage dimension of particles is in a range of any two values above.

In some embodiments, particles are porous. Characteristic pore size(e.g., pore widths or lengths) of particles can be about 5000 nm, about3000 nm, about 2000 nm, about 1000 nm, about 500 nm, about 400 nm, about300 nm, about 200 nm, about 100 nm, about 80 nm, about 50, about 10 nm.In some embodiments, characteristic pore size is in a range of 200 nm to2 μm or 100 nm to 1 μm. In some embodiments, characteristic pore size isin a range of any two values above.

The impregnating liquid of a liquid-impregnating surface may beoil-based or water-based (i.e., aqueous). The liquid may be chosen for agiven application based on its properties. In certain embodiments, theimpregnating liquid is an ionic liquid (e.g., BMI-IM). Other examples ofpossible impregnating liquids include hexadecane, vacuum pump oils(e.g., FOMBLIN® 06/6, KRYTOX® 1506) silicon oils (e.g., 10 cSt or 1000cSt), fluorocarbons (e.g., perfluoro-tripentylamine, FC-70),shear-thinning fluids, shear-thickening fluids, liquid polymers,dissolved polymers, viscoelastic fluids, and/or liquid fluoroPOSS. Inone embodiment, the impregnating liquid is made shear thickening withthe introduction of nano particles. A shear-thickening impregnatingliquid may be desirable for preventing impalement and resisting impactfrom impinging liquids, for example. To minimize evaporation of theimpregnating liquid from the surface, it may be desirable to use animpregnating liquid that has a low vapor pressure (e.g., less than 0.1mmHg, less than 0.001 mmHg, less than 0.00001 mmHg, or less than0.000001 mmHg). In certain embodiments, the impregnating liquid has afreezing point of less than −20° C., less than −40° C., or about −60° C.In certain embodiments, the surface tension of the impregnating liquidis about 15 mN/m, about 20 mN/m, or about 40 mN/m. In certainembodiments, the viscosity of the impregnating liquid is from about 10cSt to about 1000 cSt.

The impregnating liquid may be introduced to the surface using aconventional technique for applying a liquid to a solid. In certainembodiments, a coating process, such as a dip coating, blade coating, orroller coating, is used to apply the impregnating liquid. Alternatively,the impregnating liquid may be introduced and/or replenished by liquidmaterials flowing past the surface. In preferred embodiments, after theimpregnating liquid has been applied, capillary forces hold the liquidin place.

In certain embodiments, a texture may be applied to a substrate to forma surface with solid features. Applying the texture may include:exposing the substrate to a solvent (e.g., solvent-inducedcrystallization), extruding or blow-molding a mixture of materials,roughening the substrate with mechanical action (e.g., tumbling with anabrasive), spray-coating, polymer spinning, depositing particles fromsolution (e.g., layer-by-layer deposition and/or evaporating away liquidfrom a liquid and particle suspension), extruding or blow-molding a foamor foam-forming material (e.g., a polyurethane foam), depositing apolymer from a solution, extruding or blow-molding a material thatexpands upon cooling to leave a wrinkled or textured surface, applying alayer of material onto a surface that is under tension or compression,performing non-solvent induced phase separation of a polymer to obtain aporous structure, performing micro-contact printing, performing laserrastering, performing nucleation of the solid texture out of vapor(e.g., desublimation), performing anodization, milling, machining,knurling, e-beam milling, performing thermal or chemical oxidation,and/or performing chemical vapor deposition. In certain embodiments,applying the texture to the substrate includes spraying a mixture ofedible particles onto the substrate. In certain embodiments,impregnating the matrix of features with the liquid includes: sprayingthe encapsulating liquid onto the matrix of features, brushing theliquid onto the matrix of features, submerging the matrix of features inthe liquid, spinning the matrix of features, condensing the liquid ontothe matrix of features, depositing a solution comprising the liquid andone or more volatile liquids, and/or spreading the liquid over thesurface with a second immiscible liquid. In certain embodiments, theliquid is mixed with a solvent and then sprayed, because the solventwill reduce the liquid viscosity, allowing it to spray more easily andmore uniformly. Then, the solvent will dry out of the coating. Incertain embodiments, the method further includes chemically modifyingthe substrate prior to applying the texture to the substrate and/orchemically modifying the solid features of the texture. For example, themethod may include chemically modifying with a material having contactangle with water of greater than 70 degrees (e.g., hydrophobicmaterial). The modification may be conducted, for example, after thetexture is applied, or may be applied to particles prior to theirapplication to the substrate. In certain embodiments, impregnating thematrix of features includes removing excess liquid from the matrix offeatures. In certain embodiments, removing the excess liquid includes:using a second immiscible liquid to carry away the excess liquid, usingmechanical action to remove the excess liquid, absorbing the excessliquid using a porous material, and/or draining the excess liquid off ofthe matrix of features using gravity or centrifugal forces.

Liquid-impregnated surfaces are useful for reducing viscous drag betweena solid surface and a flowing liquid. In general, the viscous drag orshear stress exerted by a liquid flowing over a solid surface isproportional to the viscosity of the liquid and the shear rate adjacentto the surface. A traditional assumption is that liquid molecules incontact with the solid surface stick to the surface, in a so-called“no-slip” boundary condition. While some slippage may occur between theliquid and the surface, the no-slip boundary condition is a usefulassumption for most applications. In certain embodiments,liquid-impregnated surfaces are desirable as they induce a large amountof slip at the solid surface. Drag reductions of as much as 40% may beachieved due to this slippage.

In certain embodiments, impregnating a liquid within the textures of aliquid-impregnated surface prevents or reduces nucleation in theseregions. The reduction in nucleation is enhanced where liquid covers thetops of the solid features of the liquid-impregnated surface.Furthermore, in certain embodiments, liquid-impregnated surfaces havelow roll-off angles (i.e., the angle or slope of a surface at which adroplet in contact with the surface will begin to roll or slide off thesurface). The low roll-off angles associated with liquid-impregnatedsurfaces allow droplets in contact with the surface to easily roll offthe surface before the liquid can accumulate on the surface. In certainembodiments, liquid-impregnated surfaces are used to providehydrate-phobicity, thereby preventing or minimizing the formation ofhydrates. In certain embodiments, liquid-impregnated surfaces are usedto provide salt-phobicity, thereby preventing or minimizing theformation of salts or mineral scale.

In certain embodiments, liquid-impregnated surfaces are used to reduceviscous drag between a solid surface and a flowing liquid. In certainembodiments, a liquid-impregnated surface is used to provide lubricationbetween the liquid-impregnated surface and a substance in contact withthe surface (or the surface itself, where one liquid-impregnated surfacerubs against another liquid-impregnated surface, or parts of theliquid-impregnated surface rub against each other). For example,liquid-impregnated surfaces may provide significant slip/lubricationadvantages when in contact with a substance that is a non-Newtonianmaterial, a Bingham plastic, a thixotropic fluid, and/or ashear-thickening substance.

Liquid-impregnated surfaces may also provide anti-fouling and/orself-cleaning. Liquid-impregnated surfaces may also be used to promotethe condensation of moisture.

As used herein, emerged area fraction ϕ is defined as a representativefraction of the projected surface area of (a representative fraction of)the liquid-impregnated surface corresponding to non-submerged solid atequilibrium (or pseudo-equilibrium). The term “equilibrium” as usedherein refers to the condition in which the average thickness of theimpregnating film does not substantially change over time due todrainage by gravity when the substrate is held away from horizontal, andwhere evaporation is negligible (e.g., if the liquid impregnated liquidwere to be placed in an environment saturated with the vapor of thatimpregnated liquid). Similarly, the term “pseudo-equilibrium” as usedherein refers to the same condition except that evaporation may occur.

In general, a “representative fraction” of a surface refers to a portionof the surface with a sufficient number of solid features thereupon suchthat the portion is reasonably representative of the whole surface. Incertain embodiments, a “representative fraction” is at least a tenth ofthe whole surface.

In certain embodiments, ϕ is zero (there is a layer of liquid over thetop of the solid features which may be, for example, at least 1 nm, atleast 5 nm, at least 10 nm, or at least 100 nm in thickness). In certainembodiments of the present invention, ϕ is less than 0.30, 0.25, 0.20,0.15, 0.10, 0.05, 0.01, or 0.005. In certain embodiments, ϕ is greaterthan 0.001, 0.005, 0.01, 0.05, 0.10, 0.15, or 0.20. In certainembodiments, ϕ is in a range of about 0 and about 0.25. In certainembodiments, ϕ is in a range of about 0 and about 0.01. In certainembodiments, ϕ is in a range of about 0.001 and about 0.25. In certainembodiments, ϕ is in a range of about 0.001 and about 0.10.

In some embodiments, the liquid-impregnated surface is configured suchthat cloaking by the impregnating liquid can be either eliminated orinduced, according to different embodiments described herein.

As used herein, the spreading coefficient, S_(ow(a)) is defined asγ_(wa)-γ_(wo)-γ_(oa), where γ is the interfacial tension between the twophases designated by subscripts w, a, and o, where w is water, a is air,and o is the impregnating liquid. Interfacial tension can be measuredusing a pendant drop method as described in Stauffer, C. E., “Themeasurement of surface tension by the pendant drop technique,” J. Phys.Chem. 1965, 69, 1933-1938, the text of which is incorporated byreference herein. Exemplary surfaces and its interfacial tensionmeasurements (at approximately 25° C.) are shown in Appendix D, inparticular, Table S2.

Without wishing to be bound to any particular theory, impregnatingliquids that have S_(ow(a)) less than 0 will not cloak, resulting in noloss of impregnating liquids, whereas impregnating liquids that haveS_(ow(a)) greater than 0 will cloak matter (condensed water droplets,bacterial colonies, solid surface) and this may be exploited to preventcorrosion, fouling, etc. In certain embodiments, cloaking is used forpreventing vapor-liquid transformation (e.g, water vapor, metallicvapor, etc.). In certain embodiments, cloaking is used for inhibitingliquid-solid formation (e.g., ice, metal, etc.). In certain embodiments,cloaking is used to make reservoirs for carrying the materials, suchthat independent cloaked materials can be controlled and directed byexternal means (like electric or magnetic fields).

In certain embodiments, lubricant cloaking is desirable and is used ameans for preventing environmental contamination, like a time capsulepreserving the contents of the cloaked material. Cloaking can result inencasing of the material thereby cutting its access from theenvironment. This can be used for transporting materials (such asbioassays) across a length in a way that the material is notcontaminated by the environment.

In certain embodiments, the amount of cloaking can be controlled byvarious lubricant properties such as viscosity, surface tension.Additionally or alternatively, we can control the de-wetting of thecloaked material to release the material. Thus, it is contemplated thata system in which a liquid is dispensed in the lubricating medium at oneend, and upon reaching the other end is exposed to environment thatcauses the lubricant to uncloak.

In some embodiments, an impregnating liquid can be selected to have aS_(ow(a)) less than 0. Exemplary impregnating liquids include, but arenot limited to, tetrachloroethylene (perchloroethylene), phenylisothiocyanate (phenyl mustard oil), bromobenzene, iodobenzene,o-bromotoluene, alpha-chloronaphthalene, alpha-bromonaphthalene,acetylene tetrabromide, 1-butyl-3-methylimidazoliumbis(trifluoromethylsulfonyl) imide (BMIm), tribromohydrin(1,2,3-tribromopropane), tetradecane, cyclohexane, ethylene dibromide,carbon disulfide, bromoform, methylene iodide (diiodomethane), stanolax,Squibb's liquid petrolatum, p-bromotoluene, monobromobenzene,perchloroethylene, carbon disulfide, phenyl mustard oil,monoiodobenzene, alpha-monochloro-naphthalene, acetylene tetrabromide,aniline, butyl alcohol, isoamyl alcohol, n-heptyl alcohol, cresol, oleicacid, linoleic acid, amyl phthalate and any combination thereof.

Referring to FIG. 1 , a schematic cross-sectional view and thecorresponding top view of a liquid-impregnated surface that is partiallysubmerged is shown. The upper left drawing of FIG. 1 shows across-sectional view of a row of cone-shaped solid features. Theprojected surface area of the non-submerged solid 102 is illustrated asshaded areas of the overhead view, while the remaining non-shaded arearepresents the projected surface area of the submergedliquid-impregnated surface 100. In addition to the projection surfacearea of this row of solid features, other solid features placed in asemi-random pattern are shown in shade in the overhead view. Similarly,the cross-section view of a row of evenly spaced posts is shown on theright of FIG. 1 . Additional rows of well-patterned posts are shown inshade in the overhead view. As demonstrated, in some embodiments of thepresent invention, a liquid-impregnated surface includes randomly and/ornon-randomly patterned solid features.

In certain embodiments, a medical device or medical implement exhibitsthe nucleation show in FIG. 1 on its surface. The device's surfacecomprises an array of micro-scale or nano-scale solid features spacedsufficiently close to contain an impregnating liquid in between them.The impregnating liquid fills the spaces between the solid features, andthe surface stably holds the impregnating liquid in place in between thesolid features regardless of the orientation of the surface. In someimplementations, the particles have an average dimension of 5 microns to50 microns. In some implementations, the particles are arranged withaverage spacing of about 10 microns to about 30 microns between adjacentparticles or clusters of particles.

In certain embodiments, the particles are coated onto the medical deviceor medical implement's surface by spray coating the surface with animpregnating liquid solution. The spray coating may apply a uniform coatof impregnating liquid to the surface of the medical device or medicalimplement. In certain implementations, the impregnating liquid may bespray coated onto the surface of the medical device in multiple stages.In certain implementations where the impregnating solution is composedof several different solutions, the various constituent solutions of theimpregnating liquid may be spray coated onto the target surface indifferent stages.

The applications of liquid-impregnated surfaces for inhibitingnucleation may include, for example, preventing of nucleation of plaqueon teeth, dentures, braces, or retainers. The applications ofliquid-impregnated surfaces my also include, for example, preventingfibrosis on artificial implants. Furthermore, applications may alsoinclude preventing thrombosis on surfaces in contact with blood, orsurfaces of tubes or artificial arteries or stents, which clog frombuild up of cholesterol or other solid-like materials. These surfaceswould benefit from a more lubricated interface.

In some embodiments, the liquid-impregnated surface is created byapplying a uniform layer of the impregnating liquid to a surface. Incertain implementations, this surface may be human or animal tissue. Auniform layer of impregnating liquid may be sprayed onto a surface tocreate a uniform liquid-impregnated surface coating.

In some embodiments, the liquid-impregnated surface coating may beapplied to the internal surface of a syringe for emptying out thecontents of the syringe. For example, the internal surface of thesyringe cylinder's barrel may be coated with the impregnating liquid.This will reduce the attractive forces between contents of the syringeand internal surface of the syringe cylinder's barrel to expel themaximum amount of the syringe's contents with less applied plungerforce.

In some embodiments, the liquid-impregnated surface coating may beapplied to an artificial or natural lining for artery walls to preventplaque formation. The lining may be coated with the impregnating liquidin such a manner that does not allow plaque to stick to the lining ofthe artery walls easily. The impregnating liquid may be applied to thelining of the artery walls by pumping the artery walls with theimpregnating liquid solution or by any surgical procedure.

In some embodiments, the liquid-impregnated surface coating may beapplied to IV drips, the lining of IV tubes and the interior surfaces ofIV bags. Such a coating would allow the content of an IV bag and/or tubeto easily slide along the IV bag and tube with minimal waste of thecontent. By increasing the slipperiness of the IV lining, theliquid-impregnated surface coating reduces the attractive forces betweenthe IV tubes and bags and their contents. This allows the content to beeasily dispensed. For example, medical practitioners are frequentlyunable to convey an adequate flow rate of drugs to the patient becausethey cannot afford to put in a larger-gauge IV. Creation of aliquid-impregnated surface in the IV tube provides medical practitionerswith the ability to convey an adequate flow rate of drugs to a patientwithout using a larger-gauge IV.

In some embodiments, the liquid-impregnated surface coating may beapplied to colostomy bags. This allows for smooth reception of fecaldischarge after colostomy more easily and reduces discomfort to thepatient.

In some embodiments, the liquid-impregnated surface coating may beapplied to teeth to prevent buildup of plaque. By applying such acoating, food particles and other plaque will be less likely to stick toteeth, thereby increasing dental health of the subject.

In some embodiments, the liquid-impregnated surface coating may beapplied to metal or metallic surgical instruments, as shown by theexperiment documented in FIGS. 2A and 2B as discussed below. Applyingsuch a coating to surgical instrument allows bodily fluids such as bloodto be repelled off the coated surgical instruments and allows theinstrument to remain clean.

In some embodiments, the liquid-impregnated surface coating may beapplied to bandages in order to allow the bandages to be easily removedfrom the skin without causing discomfort to the patient. For instance,bandages with such a liquid-impregnated surface coating do not becomeglued to the wound or skin very tightly over time and pressure and canbe easily removed.

In some embodiments, the liquid-impregnated surface coating may beapplied to blood pumps. Shear forces encountered in pumping blood andother biological fluids often damage or destroy cells by mechanicallyripping them apart. The liquid-impregnated surface coating significantlyreduced the shear forces at the surfaces of the pump to prevent damageof cells and other biological structures.

In some embodiments, the liquid-impregnated surface coating may beapplied to lab supplies and pharmaceuticals in order for them to remainclean and prevent foreign substances from sticking to them.

In some embodiments, the liquid-impregnated surface coating may beapplied to pills and capsules for ease of swallowing, as shown by theexperiment documented in FIGS. 3A and 3B as discussed below. Applyingsuch a coating to pills allows the coated pills to easily slide alongthe tongue and esophagus tissue by reducing the frictional force betweenthe pill and human tissue.

In some embodiments, the liquid-impregnated surface coating may beapplied to micropipettes, pipettes, pipette tips, small volumecontainers of biological fluids and samples. For small-volume containersand micropipettes, the proportion of the contents that remains stuck tothe container represents a significant fraction of the total volume ofthe container. Furthermore, the contents are often expensive andlabor-intensive to obtain. Applying the impregnated liquid coating tothe interior surfaces of these containers and pipette tips allows thecontents to be easily expelled from these containers with minimal waste.Similarly, the coating may also be applied to the contents of thesecontainers, especially DNA and RNA strands which will aid in the easyexpulsion of these compounds from the small volume containers.

In some embodiments, the liquid-impregnated surface coating may beapplied to microfluidic devices. Often microfluidic channels becomeclogged with the contents being passed through these channels. Bycoating the microfluidic channels with liquid-impregnated surfacecoating, the contents of these microfluidic channels do not clog thechannels and the microfluidic devices can remain operation for a longerperiod of time without any maintenance.

In some embodiments, the liquid-impregnated surface coating may beapplied to dialysis tubes and other components of dialysis machines tofacilitate easier for waste and excess water removal from the blood.

In some embodiments, the liquid-impregnated surface coating may beapplied to any surgical tools that are inserted into the body such asendoscopes, stents, syringe needles, stents, catheters, tracheotomytubes, and intubation devices. Such a coating, when applied to thesesurfaces, allows for a much easier insertion into the body withoutcausing any undesired tears in body tissue. Such a coating allows formore comfortable insertion of intubation equipment. The encapsulatedliquid in the coating may also contain mid antiseptic and an anestheticthat would allow for the local area of insertion to be anesthetized andclean while the surgical tool is being inserted. An experimentedconducted using polypropylene sheets, used to simulate the surface of asurgical instrument, in contact with a steak, used to simulate humantissue, is shown in FIGS. 4A and 4B as discussed below.

In some embodiments, the liquid-impregnated surface coating may beapplied to creams, prescription creams, ointments, Neosporin, tripleantibiotic ointment, burn relieving cream, anti-itch cream, aloe-veragel, sunscreen lotion, and other lotions. The coating may also beapplied to containers of ointments, lotions, and creams. Such a coatingwould allow these chemicals to be easily dispensed and would prevent thelast few drops of such cream, lotion of ointment to stick to thecontainer walls.

In some embodiments, the liquid-impregnated surface coating may beapplied to medical supplies, gloves, bandages for covering open wounds,bandages for skin conditions, medical implants, implant coatings inorder to keep them clean from foreign particles.

In some embodiments, the liquid-impregnated surface coating may beapplied to medical device surfaces, artificial heart, and artificialorgans to prevent buildup of organic matter on these devices.

In some embodiments, the liquid-impregnated surface coating may beapplied to prosthetics and self-lubricating joints in order to keep themfree of dirt and organic matter buildup that could deteriorate effectiveoperation.

In some embodiments, the liquid-impregnated surface coating may beapplied to orthodontic tools such as a retainer, a tooth mold, dentures,dental braces, invisible braces. The surface coating can avoid plaquebuildup on the surfaces of these orthodontic tools improving dentalhealth and hygiene.

In some embodiments, the liquid-impregnated surface coating may beapplied to bridges and wetted surfaces to avoid biofouling.

In some embodiments, the encapsulated liquid in the liquid-impregnatedsurface coating may be antiseptic and antibacterial in order to allowthe surfaces to remain clean. This is particularly important in medicalapplications where the cleanliness of medical devices is paramount.

In some embodiments, the liquid-impregnated surface coating may beapplied to adhesive strips. Liquid impregnated surfaces have strongcapillary adhesive forces in the normal direction. The lateral forcesdepend on the impregnated liquid viscosity. An extremely high viscosityimpregnated liquid can behave essentially as a solid, preventingsliding, and therefore the surface would behave similarly to tape. Lowviscosity fluids slide easily, thus resulting in an surface that behaveas an adhesive in the normal direction but slides laterally.Alternatively, the textured surface could be encapsulated with liquidthat can solidify or cure (i.e., as an epoxy). Thus a curable liquidencapsulated surface could be as convenient to apply as a conventionaltape, but have the strength of epoxy.

In some embodiments, the liquid-impregnated surface coating may beapplied to condoms. The protective coating could allow for reducedfriction during intercourse and could prevent tearing. Additionally, thesurface coating could be applied to similar adult paraphernalia that isinserted into bodily orifices to reduce friction and minimize tearing.

In some embodiments, the liquid-impregnated surface coating may beapplied to drug release patches. This product might appear similar to aBand-aid, but the white portion of the Band-aid would be replaced with aliquid encapsulated surface. The encapsulated liquid can be medicationor drug. It can then be applied to the skin to deliver the medication.

In some embodiments, the liquid-impregnated surface coating may beapplied to cosmetic products such as nail polish, shampoo, conditioner,body wash, hair gel, facemasks, and toothpaste. Applying such a coatingto these cosmetic products allows them to repel dust and prevents dustthat would otherwise be attracted to them to be applied to the body.

EXPERIMENTAL EXAMPLES Example 1

FIG. 2 shows experimental measurements of blood droplet repulsion fromtweezers coated with the liquid-impregnated surface coating. As shown inFIG. 2A, two identical plastic tweezers, tweezer 202 and tweezer 204 aredipped into container 206 which is filled with two drams of pig blood.Tweezer 202 is uncoated as a control tweezer. Tweezer 204 is coated withthe liquid-impregnated surface coating. Tweezers 202 and 204 are dippedinto container 206 at the same time and removed at the same time.Tweezers 202 and 204 are held in the same hand.

FIG. 2B shows the effect of the surface coating on tweezer 204 when bothtweezers 202 and 204 are removed from container 206 of pig blood. Theuncoated tweezer 202 is stained with blood residue. Theliquid-impregnated surface coated tweezer 204 shed the majority of theblood away with minimal reside as soon as tweezer 204 was withdrawn fromcontainer 204.

The experiment of FIG. 2 demonstrates that liquid-impregnated surfacescan be engineered to keep medical devices clean of bodily fluids. Thisis helpful in keeping medical equipment and surgical tools sterile.

Example 2

This example demonstrates liquid-impregnated surface pills are easier toswallow than uncoated pills. It demonstrates this by comparing thesliding speed of a liquid-impregnated surface coated pill on a piece ofsteak against the sliding speed of an uncoated pill.

FIG. 3A shows a screenshot of a video taken to document coated pill 302and uncoated pill 304 sliding on steak to mimic the esophagus and tonguetissue. The coated and uncoated pills were placed in a parallelorientation on two pieces of steak, steak 306 and 308 as show in FIG.3A. Steak 306 and 308 were placed on an incline of 65°. Pill 302 wascoated with a liquid impregnated surface (carnauba wax and ethyl oleate)whereas pill 304 was uncoated as a control.

In particular, tweezers were used to pick up the cylindrical pale yellowpills (Vitacost Alpha Lipoic Acid & Acetyl L-Carnitine HCl—1600 mg perserving). Carnauba wax was sprayed onto pill 302 for three seconds toapply uniform coating of the liquid-impregnated coating. Nitrogen gaswas blown across pill 302 to allow time to dry coating prior toapplication of ethyl oleate. Ethyl oleate was sprayed onto pill 302 forthree seconds to apply uniform coating. Subsequently, uncoated pill 304was placed onto steak 308. Liquid-impregnated surface coated pill 302was placed onto steak 306. Pills 302 and 304 were placed at top of theirrespective steak. The orientation of the pills was perpendicular toruler 310. Subsequently, steaks 306 and 308 were adjusted to a 65 degreeinclined plane. FIG. 3A shows pills 302 and 304 at zero seconds as soonas they were placed on the top of the steaks.

FIG. 3B shows a screenshot 3.5 seconds after pills 302 and 304 wereplaced on the top of the steaks. At this time, coated pill 302 reachedthe bottom of steak 306 while uncoated pill 304 remained at the top ofsteak 308. Pill 302 started sliding slowly but rapidly accelerated to arate of ˜4.5 cm/s (calculated based on a travel distance of 7 cm over1.5 seconds. The uncoated pill remained at the top of the steakthroughout the experiment.

The experiment of FIG. 3 demonstrates that liquid-impregnated surfacecoatings on pills helps the pill slide on top of animal tissue such assteak which mimics the surface structure of the human tongue andesophagus since the uncoated pill did not travel any distance on thesteak at the same inclined angle.

Example 3

This example demonstrates the low friction between liquid-impregnatedsurfaces and flesh. This is demonstrated by comparing the sliding speedof raw eye round steak on a liquid impregnated surface with the slidingspeed of another raw eye round steak on an uncoated surface. A video wastaken was to document the steaks' motion on uncoated and coatedpolypropylene sheets.

This experiment was performed by first cutting a 12″×12″ polypropylene(PP) sheet (Gauge=0.060″) into two 6″×12″ sheets, sheet 406 and 408.Carnauba wax was sprayed onto sheet 408 for fifteen to thirty second toapply uniform coating. Subsequently, ethyl oleate was sprayed onto sheet408 for thirty to forty five second to apply uniform coating. Sheet 406was left uncoated as control. Sheet 406 was placed next to sheet 408 andboth sheets 406 and 408 were placed on a 45 degree incline. Steak 402was placed on top of sheet 406 and steak 404 was placed on top of sheet408. The beginning of the meat steaks were four inches from the top ofthe PP sheets. Video of the meat travelling was taken to document thedifference between uncoated and coated PP sheets. FIG. 4A shows a videoframe at time zero when the steaks were placed on top of the PP sheets.FIG. 4B shows a video frame one hundred and thirty one seconds after theframe shown in FIG. 4B. FIG. 4B shows that steak 404 has reached thebottom of sheet 408 while uncoated steak 402 still remains near the topof the PP sheet 406.

Time was measured for steak to travel eight inches to the bottom of thePP sheet. Steak 404 on PP sheet 408 took 131 seconds to travel to bottomof sheet. The average velocity of liquid-impregnated surface coatedsteak 404 on sheet 408 was 0.055 inches/sec. Uncoated steak 402 on PPsheet 406 slightly moved but remained about seven inches from the bottomof the sheet after 2 minutes and 30 seconds. Upon additional time (˜5mins), the steak did not appear to move any further down the inclinedramp.

The experiment of FIG. 4 demonstrates that liquid-impregnated surfacecoatings on surfaces helps animal flesh slide down the surface moreeasily than on uncoated surfaces. This provides evidence to prove thatsuch a liquid-impregnated surface coating provides reduction of shearforces to prevent damage to cells and other biological structures inblood or other biological fluids being pumped.

Example 4

FIGS. 5A-D illustrate a mold-release experiment using concrete and aliquid-impregnated surface coated mold. In some embodiments, theliquid-impregnated surface coating may be applied to orthodontic toolssuch as a tooth mold. A heavily detailed plastic bottle in the shape ofa monkey, complete with crevices and structures, was used to demonstrateliquid-impregnated surfaces as mold release/non-stick coatings as shownin FIG. 5A. The approximately 500 ml HDPE, monkey-shaped bottle wassawed in half with a reciprocating saw to create a front half and a backhalf as shown in FIG. 5B. The back half of the bottle was coated with aliquid impregnated surface, described below, while the front halfremained uncoated.

A liquid impregnated solution was sprayed onto the back half of thebottle. The liquid-impregnated solution was prepared by using adding 1.5g of fluorinated wax (HF diblock grey, Toko) to 80 ml of toluene andheated on a hot plate until total dissolving of the wax. Next, thesolution was sonicated for 5 minutes and was let to cool down to roomtemperature. Finally 10 g of PTFE particles (1 μm size, Sigma) wereadded and sonicated for 5 minutes more. The solution was sprayed ontothe mold to create a coating of approximately 10 um thickness, and thenGalden HT 200 was sprayed to impregnate and fill the textures.

Rapid setting concrete was mixed per the manufacturer's instructions andpoured into each mold until full as shown in FIG. 5C. The concrete wasleft to cure for approximately 15 minutes at room temperature (70° F.)and each mold was turned upside-down on the counter. We then pulled thecoated plastic mold from the hardened concrete easily and completely,leaving behind a cast of the inside of the bottle as shown in FIG. 5D.The uncoated side would not release from the mold.

Example 5

FIG. 6 illustrates a solid-to-solid adhesion experiment. The lateralforces (sliding) depend on the impregnated liquid viscosity. Anextremely high viscosity impregnated liquid can behave essentially as asolid, preventing sliding, and there for the surface would behavesimilarly to tape (FIG. 6 ). Low viscosity fluids slide easily, thusresulting in a surface that behave as an adhesive in the normaldirection but slides laterally (Imagine an air hockey table where themallets can easily slide but are extremely difficult to pull off).

The adhesion force was obtained by measuring the force needed toseparate a liquid-impregnated surface from a glass slide in the normaldirection. A glass slide was attached to the scale and theliquid-impregnated surface was pulled off of the surface in the normaldirection. Capillarity forces due to the impregnated liquid resulted inadhesive strength of τ_(adh)=1.1±0.1 Pa. The liquid-impregnated surfacewas prepared using a lithography patterned array of square posts of 10um width and height, and spaced by 25 um. 10 cSt silicone oil wasimpregnated into the surface.

We measured the static coefficient of friction, μ_(s), between two solidmaterials with three different configurations. The first interface issilicon on PET (configuration 1), the second interface is silicon withthe liquid impregnated surface (for which the normal adhesion wasmeasured) on PET, and the third interface (configuration 3) is glasssprayed with carnauba wax to create a textured surface that wasimpregnated with ethyl oleate. The PET surface beneath was coated with athin film of toothpaste to yield a chemistry that is preferentiallycontacted by ethyl oleate over the carnauba wax, insuring a stableliquid film between the solid materials. The coefficient of friction foreach of these configuration was calculated as μ_(s)=tan α_(slide), whereα_(slide) is the angle at which the surface first begins to slide. Aweight was attached to the top of each surface resulting in a force perunit area of the top surface of around 520±10 N/m² on each surface. Theslide-off angles, α_(slide), for configuration 1, 2, and 3, were 24°,16°, and 7° respectively resulting in coefficients of friction,μ_(s)=tan α_(slide) of 0.44, 0.29, and 0.12 respectively. Thusconfigurations 2 and 3 both produced lower coefficients of friction thanthe direct solid/solid interface (configuration 1) Configuration 3, forwhich the chemistry of the bottom was modified with a layer oftoothpaste, had the lowest friction—presumably because the a thin filmof liquid (ethyl oleate) is stable between toothpaste and the carnaubawax, and therefore there was no solid-to-solid contact.

EQUIVALENTS

While the invention has been particularly shown and described withreference to specific preferred embodiments, it should be understood bythose skilled in the art that various changes in form and detail may bemade therein without departing from the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:
 1. A catheter, comprising: an interior surfacecomprising an impregnating liquid and a plurality of micro-scale and/ornano-scale solid features spaced sufficiently close to stably containthe impregnating liquid therebetween, wherein said impregnating liquidfills spaces between said solid features, wherein said interior surfacestably contains said impregnating liquid between said solid features,wherein said impregnating liquid is substantially held in place betweensaid plurality of solid features regardless of orientation of saidinterior surface and regardless of flow, passage, or removal of fluidsthrough, into, or out of said catheter, wherein said interior surface ispartially submerged by the impregnating liquid, and wherein the interiorsurface is nonwetting to a biological fluids wherein 0<ϕ<0.3, where is asurface area fraction of the surface non-submerged by said impregnatingliquid, and wherein said surface is a textured surface and said solidfeatures are engineered protrusions or engineered particles of saidtextured surface.
 2. The catheter of claim 1, wherein said interiorsurface is configured to facilitate the flow, passage, or removal offluids through, into, or out of said catheter.
 3. The catheter of claim1, wherein the solid features comprise particles having an averagedimension in a range of 1 micron to 50 microns.
 4. The catheter of claim1, wherein the impregnating liquid comprises at least one memberselected from the group consisting of ethyl oleate, an ester, a fattyacid, a fatty acid derivative, a vegetable oil (e.g., olive oil, lightolive oil, corn oil, soybean oil, rapeseed oil, linseed oil, grapeseedoil, flaxseed oil, canola oil, peanut oil, safflower oil, sunfloweroil), a terpene, phenyl isothiocyanate (phenyl mustard oil),bromobenzene, iodobenzene, o-bromotoluene, alpha-chloronaphthalene,alpha- bromonaphthalene, acetylene tetrabromide,1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (BMIm),tribromohydrin (1,2,3-tribromopropane), ethylene dibromide, carbondisulfide, bromoform, methylene iodide (diiodomethane), stanolax,Squibb's liquid petrolatum, p-bromotoluene, monobromobenzene,perchloroethylene, carbon disulfide, phenyl mustard oil,monoiodobenzene, alpha- monochloro-naphthalene, acetylene tetrabromide,aniline, butyl alcohol, isoamyl alcohol, n-heptyl alcohol, cresol, oleicacid, linoleic acid, and amyl phthalate.
 5. The catheter of claim 1,wherein the solid features comprise one or more members selected fromthe group consisting of wax, carnauba wax, beeswax, candelilla wax, zein(from corn), dextrin, cellulose ether, hydroxyethyl cellulose,hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose,hydroxypropyl methyl cellulose (HPMC), ethyl hydroxyethyl cellulose,insoluble fiber, purified wood cellulose, micro-crystalline cellulose,kaolinite (clay mineral), Japan wax, pulp, ferric oxide, iron oxide,sodium formate, sodium oleate, sodium palmitate, sodium sulfate, ametal, a polymer, a ceramic solid, a fluorinated solid, an intermetallicsolid, and a composite solid PDMS, cyclic olefin polymer, polypropylene,PVC, PET, HDPE, polyimide, PMMA, glass, Perspex, Plexiglass, andPolymacon.
 6. The catheter of claim 5, wherein the pulp is spongy partof plant stems.
 7. The catheter of claim 1, wherein the impregnatingliquid comprises an additive to prevent or reduce evaporation of theimpregnating liquid.
 8. The catheter of claim 1, wherein the surfaceprovides reduction of shear forces to prevent damage to cells and/orother biological structures in blood or other biological fluids beingpumped thereby or therethrough.
 9. The catheter of claim 1, wherein saidimpregnating liquid comprises a drug.
 10. The catheter of claim 1,wherein the impregnating liquid is curable and can be converted to asolid by curing.
 11. The catheter of claim 1, wherein the drug isantiseptic and/or an antibacterial, or bioactive components.
 12. Thecatheter of claim 11, wherein the curing is exposure to heat.
 13. Thecatheter of claim 1, wherein Sow(a)<0, where Sow(a) is spreadingcoefficient, defined as γwa-γwo-γou , where y is the interfacial tensionbetween the two phases designated by subscripts w, a, and o, where w iswater, a is air, and o is the impregnating liquid.
 14. The catheter ofclaim 13, wherein Sow(a)<0.
 15. The catheter of claim 1, wherein one orboth of the following holds: (i) θos(w),receding=0; and (ii)θos(a),receding=0 and θos(w),receding=0, where θos(w),receding isreceding contact angle of the impregnating liquid (subscript ‘o’) on thesurface (subscript ‘s’) in the presence of water (subscript ‘w’), andwhere θos(a),receding is receding contact angle of the impregnatingliquid (subscript ‘o’) on the surface (subscript ‘s’) in the presence ofair (subscript ‘a’).
 16. The catheter of claim 15, wherein theimpregnating liquid is oil.
 17. The catheter of claim 1, wherein saidcatheter prevents thrombosis on surfaces in contact with blood.
 18. Thecatheter of claim 1, wherein the catheter provides an anti-foulingand/or self-cleaning surface.
 19. The catheter of claim 1, wherein thecatheter is configured to contain ointments, lotions, creams, or gels.20. The catheter of claim 1, wherein 0.01<ϕ<0.25, where ϕ is arepresentative fraction of a projected surface area of said interiorsurface corresponding to non-submerged solid at equilibrium versus atotal projected surface area of said liquid-impregnated surfacecorresponding to non-submerged and submerged solid at equilibrium. 21.The catheter of claim 20, wherein 0.01<ϕ<0.10.
 22. The catheter of claim1, wherein the catheter comprises a tube.